SOME hardworking folks at NBC and MSNBC — who work long hours for little pay — are wondering, “Where in the world is Luke Russert?”

One insider sniped, “He was hired last year to be the youth correspondent — he got a great contract and was supposed to cover youth issues, blog and bring in young viewers, but he’s been MIA for a while. It’s like, ‘Well, that’s what you get for nepotism.’ ”

Russert, 23, was hired at the network on July 31 as a correspondent-at-large, after his beloved father, Washington bureau chief and moderator of “Meet the Press” Tim Russert, died last summer.

Luke was highly visible during the presidential campaign, but disappeared after the inauguration. He was raked over the coals when news of an “Inaugural Party Hosted by Luke Russert” at preppy DC nightclub the Rookery was announced. The party had a $95 cover and a “cheesy” invite with Russert posing as Uncle Sam in the “I Want You” pose. It also violated NBC’s ethics policies and forced the network to issue a statement noting it was not an NBC event. Russert quickly had his image deleted from the fliers.

The insider sniped, “He hasn’t even updated his blog which he’s paid a lot to do and just got on Twitter. Some youth correspondent!”

Russert’s last blog, “The Courage To Go Online” was posted Dec. 4, 2008 — and he started his Twitter account on Feb. 18, which was the date, incidentally, that Luke was last on air, interviewing Bill Clinton for President’s Day. His last tweet, “Been on the Road,” was on March 31.

Last October, Russert told MediaBistro, he was aware of the nepotism surrounding his hiring and said, “Did my name get my foot in the door? Absolutely, I’ll be the first to admit that. But has my performance and ability got my butt through the door? Yes.” Too bad he seems to have looked a gift horse in the mouth.

A rep for NBC said, “I think he’s been on since then,” but didn’t provide details.